• A-2 Boiler details query

  • Discussion relating to the NYC and subsidiaries, up to 1968. Visit the NYCS Historical Society for more information.
Discussion relating to the NYC and subsidiaries, up to 1968. Visit the NYCS Historical Society for more information.

Moderator: Otto Vondrak

  by Allen Hazen
Timz-- Thank you for reference. Edson/May is... one of the many serious holes in my reference library.
Rlsteam-- Thank you for the links! (For those who don't know about it, Rlsteam's website is avery valuable resource for anyone interested in (particularly but not solely) New York Central steam locomotives: bookmark it along with George Elwood's "Fallen Flags".)

I have seen the row of cylinders along the A-2's firebox referred to both as "overfire jets" and as "smoke consumers," so I have assumed that (in this context) the terms are equivalent: one describing the mechanism, one its function. The instruction manual is ... instructive! The New York Central seems to have thought of these appliances as things to use only under special circumstances, but I wonder whether something like them might be useful on a continuous basis. They "consume smoke" (useful if you want to look into the firebox to inspect the fire, and also if you don't want the railroad to get fined for making smoke in an urban area) by injecting more air into the smokebox (the steam jet apparently is just a mechanism to entrain air flow) topromote more complete combustion: smoke is "consumed" by burning the soot particles. But having more complete combustion is something you might reasonably want anyway! Any soot particle that goes up the smokestack is a particle of coal fuel that didn't get burned in the firebox, so didn't contribute energy to heating the boiler water: it is, in other words, wasted fuel. "More complete combustion," therefore, sounds like "improved efficiency in the use of fuel"! I know that modern (post the end of steam in North America) efforts at improving steam locomotive design (look for references to the engineer L.D. Porta, and to South African Railways locomotive "the Red Devil") have included schemes to get more air into the firebox so as to burn the fuel more efficiently: I've wondered if the "top hats" on the side of the A-2's firebox were a step in this direction, an important improvement in steam locomotive technology that (like the Giesl ejector) came too late to have more than a few experimental applications on U.S. locomotives!
  by Allen Hazen
I don't know what the device under the running board is. It looks as if it is in the middle of the pipe that starts in front of the steam delivery pipes to the cylinders, run to the device, then leaves the device (ducking out of sight behind the air reservoir) and continues back alongside the firebox below the "top hats". If forced to guess, I'd go for the pipe being for delivery of steam to the smoke consumers (or maybe to the stoker engine), and the device maybe being the machinery to control them, but that would be a guess.
As to the pipe over the valve chest... There are slightly similar pipes above the cyinders of some late Santa Fe steam locomotives, and I think I've been told that they had something to do with letting steam out of the system when the locomotive was coasting.
  by NYC_Dave
I would also like to know what is the difference between overfire jets and "smoke consumers".
The attached picture must show a one of a kind experiment on Mohawks.
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  by rlsteam
I just posted my questions to the New York Central System Historical Society members Yahoo group. We will see if we get an answer.
  by rlsteam
A reply from Rich Stoving of the New York Central System Historical Society indicates that the device under the running board is the exhaust steam injector, which makes perfect sense. The only other photo of one I could recall was on the CNR U-1-f "bullet nose" 4-8-2, where it's mounted beside the left rear driver. A search disclosed that UP 3985 also has the exhaust steam injector, which I believe must be the device located just ahead of the firebox since a pipe from the tender is running to it. The spill pipe, though, is just ahead of the cylinder for the rear "engine." See the photos here:
http://www.forecyte.com/images/exhaust_ ... ectors.jpg
  by Allen Hazen
Thank you for tracking that down! ... So I suppose the pipe from the front to the device delivers the exhaust steam. Is the pipe from the device back along the side of the firebox to bring water from the tender up to the device? (I should see whether I can find any general information about exhaust steam injectors that would help in understanding the picture! Will try to look in Bruce and the 1941 Cyclopedia: will report back if I find out anything interesting.
Exhaust steam injector serves the same function as a feedwater heater: uses some of the otherwise wasted energy of exhaust steam to pre-heat the water that goes into the boiler. I think that in an e.s.i. the exhaust steam gets mixed with the water: so it is perhaps more like an "open" f.w.h. (like the Worthington) than like the Elesco (in which the feedwater is kept in tubes to keep it separated from the steam(*)). I think the difference may be that a f.w.h. uses a pump to force the heated water into the boiler, whereas an e.s.i. uses the momentum of a jet of steam for that purpose. But I'll see if I can find out more.

Thanks again!
  by rlsteam
I think you are quite right, an exhaust steam injector is comparable to the "open" type of feedwater heater. If I am not mistaken, the Worthington SA, mounted in the smokebox, was "open" but the Worthington BL (side-mounted) was "closed." Evidently the Worthington SA was judged more efficient than the closed Elesco bundle-type, because the NYC retrofitted the J-3 Hudsons with them and, I guess, specified them for the Niagaras and late Mohawks. Other railroads, such as the Alton, also retrofitted older power (which was all they had!) with the Worthington SA.
  by Allen Hazen
Further evidence (if any were needed) that an exhaust steam injectoris analogous to an "open type" feedwater heater: this sort of item was supplied by outside suppliers (even if Alco, say, or a railroad shop built a steam locomotive, the f.w.h. or e.s.i. would have been made by an outside contractor). Much of the detailed information in the 1941 "Locomotive Cyclopedia" is in advertisements from suppliers. In the boiler attachments section of the volume, the Superheater Company(*) (which marketed its products under the brand name "Elesco") has two successive two-page spreads, of virtually the same format, with diagrams of the products superimposed on the same locomotive image, for two of its offerings: what we know as the "Elesco Feedwater Heater" (this is the highly visible design, in which the feadwater is headed in a cylinder typically mounted crosswise on the front or top of the smokebox), subtitled "A Closed-type Feedwater Heater," and their version of the exhaust steam injector, subtitled "An Open-type Feedwater Heater."

I'm not sure why the e.s.i. got called "the poor man's feed water heater": in its original form (though this seems to have been one of those areas of technology where a simple original idea got more and more complicated as it evolved!) it may have been mechanically simpler than something like the Worthington f.w.h. (which seems to have needed two different pumps, one for hot water and one for cold), so possibly its first cost and maintenace would have been cheaper. ... I don't know enough about the engineering principles involved, so this may be ENTIRELY off base, but I note that the A-2 (230 p.s.i.) had a much lower operating boiler pressure than the Niagara (275 p.s.i., i.i.r.c.), and I wonder if the choice of injector vs. feedwater pump depended in part on the boiler pressure the feed water-delivery device was intended to cope with.

Bruce's book has a paragraph on the e.s.i. at the end of its section on the history of f.w.h. development: I'll try to post an abstract later.
  by Allen Hazen
(*) So, just who were "The Superheater Company"? I've jst spent some time Googling, and am left with questions about its ownership. It was apparently founded in 1910 (as the "Locomotive Superheater Company," as you doubtless guessed from its brand name) to produce superheaters to designs deriving from the work of Wilhelm Schmidt. One thing I found said that -- in 1914 --it was majority owned by German investors. Someone on a railway-preservation forum referred to it as a Baldwin subsidiary. PERHAPS it was taken over by Americans during or after the First World War; I wonder if, in later years, it might have been a JOINT subsidiary of Alco and Baldwin. ... And I have no idea whether there was a corporate link between this U.S.-based company and the British "Superheater Company Ltd."
  by Allen Hazen
Sorry to take so long in getting around to posting on Bruce on exhaust steam injectors. His account is two paragraphs at the end of his "Feedwater Heater" section.
"Another alternate device was developed between 1920 and 1930 with the same end in view. It was known as the 'exhaust steam injector' or the 'poor man's feedwater heater.' In this device the required energy to enter the boiler was imparted to the feedwater in two stages: the first by the use of exhaust steam and the second by the use of live steam. It started as a relatively simple device, but soon became more and more complicated and is in little demand today.
"As might be expected its absorption of waste heat was less than that of the feedwater heater, even after allowing for feed-pump operation, and its efficiency was not expected to be much over 5 per cent. Its delivery temperature of about 250 Fahrenheit was a little more than that of the feedwater heater but stillless than that of the live-steam injector. And again nearly all heat used by the device was ventually returned to the boiler."
So. Alfred Bruce doesn't sound like a great enthusiast for the e.s.i. The Elesco advertisement in the 1941 "Locomotive Cyclopedia" cited earlier, on the other hand, suggests that the fuel and water savings possible by use of the e.s.i. were in the same league as what the Elesco closed-type f.w.h. afforded.
As for complexity... When the locomotive is operating at full throttle, there is lots of exhaust steam, but sometimes you have to add water to the boiler when drifting or stopped: so, the Elesco e.s.i. had the ability to use live steam instead of exhaust steam when necessary: since I don't understand injectors, I'm not sure what exactly this involved, but I imagine more pipes and more valves... and so more first cost and more to maintain.
Question for those who know more about New York Central (system) steam power than I do: was the NYC(S) a big user of exhaust steam injectors on some classes of power? If so, maybe the use of this (instead of a Worthington f.w.h.) on the A-2 was in line with standard policy. If not, its adoption is one more mystery about the A-2.
  by rlsteam
I seem to recall mention of an article a number of years ago (in TRAINS, I think) about the A-2s. It was titled something like "The Locomotive the P&LE Didn't Want." Maybe the article dealt with some of the questions being discussed here. Perhaps someone in this discussion has access to the magazine. (I don't happen to have it myself.)
  by Allen Hazen
Sounds like a potentially interesting article. Bad news: I tried to find a reference on the WWWeb (the NRMA has an online index to model railroad magazines, the "Trains" magazine website has a searchable index of... some number of railroad-y magazines, and I also looked at the list of available back issues of the NYCHS "Central Headlight"), but without success. ... There is a book about the A-2, but I don't know what it is like, and cetainly don't want to invest a large sum only to find that it is a photo-album!
  by rlsteam
I located the article, "The Unwanted Berkshires." It''s in the Spring 2004 issue of CLASSIC TRAINS magazine. My issues don't go back that far, but maybe someone here has the issue.
  by Allen Hazen
Thanks for the reference! (I probably didn't find it in the "Trains" index-- which I think does cover "Classic Trains"-- because I searched the wrong keywords!) Magazines that old are sometimes hard to find, but ... (If someone DOES have it, I'd happily trade photocopies!)